An organic single crystal dye laser and its preparation method and application

Abstract

The present invention provides an organic single crystal dye laser and a preparation method and application thereof. The organic single crystal dye laser comprises a dye single crystal, and the dye single crystal is obtained by self-assembly of organic dye molecules; in the dye single crystal, the organic dye molecules have a loose molecular arrangement structure, which can inhibit intermolecular charge transfer, thereby making stimulated radiation more likely to be achieved. The organic single crystal dye laser of the present invention has loose molecular stacking and weak π-π interaction, which can inhibit intermolecular charge transfer and maintain excellent optical gain of dye molecules, thereby achieving low-threshold laser emission; the organic dye single crystal provided by the present invention is assembled into micrometer wires, which can serve as high-quality optical resonant cavities to provide optical feedback and mode amplification for stimulated radiation of organic dye molecules. The organic single crystal dye laser of the present invention realizes optically pumped laser radiation of single crystal dyes for the first time. The present invention also provides applications of the organic single crystal dye laser.

Description

Technical Field

[0001] The invention belongs to the technical field of organic micro-nano lasers, and in particular relates to a novel organic single crystal dye laser and a preparation method thereof and an application in laser performance. Background Art

[0002] Since the advent of the first ruby ​​laser, the design and development of lasers have made rapid progress. In 1966, researchers invented dye lasers using organic dye solutions as gain media. Organic dye molecules with wide emission bands are particularly suitable for constructing tunable lasers and pulsed lasers, and have shown many advanced applications in astronomy, manufacturing, medicine, spectroscopy and other fields. In order to further meet the integration of optical devices and the safety of laser devices during transportation and storage, solid-state dye lasers have received widespread attention and development. However, current solid-state dye lasers mainly rely on dye-doped polymers as gain media, which have problems such as high defect density, low optical gain and poor stability. The single crystal structure not only has few defects, high optical gain and good stability, but also has a large refractive index and optical anisotropy, which provides broad prospects for the design of high-performance solid-state lasers. Although single-crystalline organic lasers have been realized in some organic semiconductor materials, these materials are mainly limited to a few aromatic oligomers, and in recent years, organic single-crystal semiconductor lasers have approached their performance and functional limits. In contrast, there are many types of laser dye molecules, such as common coumarin, rhodamine and cyanine derivatives. The realization of dye single crystal lasers is expected to further broaden the gain system of organic single crystal lasers. However, it is still a huge challenge to realize stimulated radiation in the single crystal state using organic dye molecules. The main reasons are as follows: the self-assembly process of dye molecules follows thermodynamic or kinetic pathways (thermodynamic products are more stable, while kinetic products are formed faster). Usually, kinetic aggregates spontaneously reorganize to thermodynamically stable states through molecular thermal motion, so thermodynamic products are easier to obtain, but thermodynamic dye aggregates often produce intermolecular charge transfer due to their compact molecular arrangement, and then suffer from severe intermolecular quenching, which makes it difficult to provide sufficient optical gain, which is not conducive to the realization of dye single crystal lasers. Summary of the invention

[0003] In order to solve the deficiencies of the prior art, the present invention provides an organic single crystal dye laser and a preparation method thereof and application in laser performance; the organic single crystal dye laser is a laser that can suppress the charge transfer of molecular self-assemblies and promote the stimulated radiation process, and can be used to prepare organic micro-nano lasers.

[0004] The present invention provides the following technical solutions:

[0005] The invention provides an organic single crystal dye laser. The organic single crystal dye laser comprises a dye single crystal. The dye single crystal is obtained by self-assembly of organic dye molecules.

[0006] According to an embodiment of the present invention, the dye single crystal has a very high crystallinity.

[0007] According to an embodiment of the present invention, the dye single crystal has low-threshold laser emission.

[0008] According to an embodiment of the present invention, in the dye single crystal, the organic dye molecules have a loose molecular arrangement structure, which can inhibit the charge transfer between molecules, thereby making it more likely to achieve stimulated radiation.

[0009] Preferably, in the molecular arrangement structure, the minimum periodic unit is formed by the parallel stacking of the organic dye molecules. Further, the distance between the parallel stacked molecules is greater than For example

[0010] According to an embodiment of the present invention, the dye single crystal has a micro-nano structure. Preferably, the micro-nano structure has typical optical waveguide characteristics, which can confine propagating photons and generate optical resonance.

[0011] Preferably, the micro-nano structure may be a micron-wire structure. Further, the length of the micron-wire structure may be 3-30 μm, the width of the micron-wire structure may be 0.8-2.5 μm, and the thickness of the micron-wire structure may be 0.3-1 μm. Exemplarily, the length of the micron-wire structure may be 3.6-15.8 μm, the width of the micron-wire structure may be 1-2.2 μm, and the thickness of the micron-wire structure may be 0.5-0.8 μm.

[0012] According to an embodiment of the present invention, the organic dye molecules are selected from organic dyes having optical gain.

[0013] Preferably, the organic dye molecule is selected from coumarin-153 (C153), for example.

[0014] According to an embodiment of the present invention, the structure of coumarin-153 is shown in Formula 1:

[0015]

[0016] According to an embodiment of the present invention, the self-assembly of the organic dye molecules includes: the organic dye molecules self-assemble under weak intermolecular forces (such as π-π bonds, hydrogen bonds, etc.) to obtain the dye single crystal.

[0017] According to an exemplary embodiment of the present invention, the organic single crystal dye laser comprises a dye single crystal, wherein the dye single crystal is obtained by self-assembly of the organic dye molecules, and the organic dye molecules are selected from coumarin-153.

[0018] Preferably, the dye single crystal is a triclinic system, and its unit cell parameters are α=80.231°, β=78.024°, γ=74.093°.

[0019] Preferably, the dye single crystal has optical gain. Further, the organic single crystal dye laser emits cyan light under the excitation of ultraviolet light (330-380 nm), for example, its maximum emission wavelength is 516 nm.

[0020] Preferably, the organic single crystal dye laser has a fluorescence quantum yield of 59.8% under excitation at 405 nm.

[0021] Preferably, in the dye single crystal, the molecular arrangement structure of the organic dye molecules is substantially as follows: Figure 4 As shown in A or B.

[0022] Furthermore, in the molecular arrangement structure, the minimum periodic unit is the parallel stacking of the organic dye molecules. Preferably, in the dye single crystal, the distance between the parallel stacked molecules is

[0023] Preferably, the dye single crystal has a micrometer wire structure. Further, the length of the micrometer wire structure may be 3-30 μm, the width of the micrometer wire structure may be 0.8-2.5 μm, and the thickness of the micrometer wire structure may be 0.3-1 μm. Exemplarily, the length of the micrometer wire may be 3.6-15.8 μm, the width of the micrometer wire may be 1-2.2 μm, and the thickness of the micrometer wire may be 0.5-0.8 μm.

[0024] Preferably, the micrometer wire structure has typical optical waveguide characteristics, confines propagating photons and generates optical resonance. Exemplarily, the dye single crystal has an optical resonant microcavity, specifically a Fabry-Perot type microcavity.

[0025] The present invention also provides a method for preparing the above-mentioned organic single crystal dye laser, the method comprising the following steps:

[0026] 1) dissolving organic dye molecules in an organic solvent to obtain a saturated organic solution;

[0027] 2) The saturated organic solution prepared in step 1) is dripped onto the substrate, and in an anti-solvent atmosphere, the organic dye molecules are self-assembled to obtain the organic single crystal dye laser.

[0028] According to an embodiment of the present invention, in step 1), the organic solvent is selected from small molecule organic solvents that can dissolve organic dye molecules.

[0029] Preferably, the organic solvent is selected from n-hexane, dichloromethane, tetrahydrofuran, toluene, acetonitrile, chloroform, preferably n-hexane.

[0030] According to an embodiment of the present invention, in step 1), the molar concentration of the organic dye molecules in the organic solvent is 1-10 mmol / L, preferably 2-4 mmol / L.

[0031] According to an embodiment of the present invention, in step 1), the method for preparing the saturated organic solution specifically comprises: dissolving organic dye molecules in an organic solvent, stirring at different temperatures to obtain organic solutions at different temperatures; and filtering to obtain a saturated organic solution.

[0032] Preferably, the stirring temperature is 30-80°C, preferably 40°C.

[0033] Preferably, the stirring speed is 800-2000 rpm, preferably 1000-2000 rpm, for example 1500 rpm.

[0034] Preferably, the stirring time is 15-60 min, preferably 30 min.

[0035] Preferably, the filtration can be performed in a device known in the art. Exemplarily, the filtration is performed in a polytetrafluoroethylene filter, and the diameter of the polytetrafluoroethylene filter is 0.1-1 μm, for example, 0.2 μm.

[0036] According to an embodiment of the present invention, in step 2), the anti-solvent atmosphere is selected from at least one of acetone, n-hexane, and ethanol, preferably ethanol.

[0037] According to an embodiment of the present invention, in step 2), the substrate is selected from substrates known in the art that can be used as base materials, for example, selected from glass plates, silicon plates, and quartz plates.

[0038] According to an embodiment of the present invention, in step 2), the temperature of the substrate is 10-30°C, for example, 20°C.

[0039] According to an embodiment of the present invention, in step 2), the self-assembly of the organic dye molecules is self-assembly induced by the volatilization of an organic solvent.

[0040] Preferably, the temperature of the self-assembly is 30-80°C, for example, 30°C, 40°C, 50°C, 60°C, 70°C or 80°C.

[0041] According to an embodiment of the present invention, in step 2), the size of the organic single crystal dye laser is controlled by the volume of the saturated solution added dropwise.

[0042] The present invention also provides applications of the above-mentioned organic single crystal dye laser, such as applications in the fields of organic micro-nano lasers, integrated optical circuits, organic lasers, etc.

[0043] The present invention also provides a micro-nano laser, which includes the above-mentioned organic single crystal dye laser.

[0044] The present invention also provides an integrated optical circuit, which includes a coherent light source, and the coherent light source includes the above-mentioned organic single crystal dye laser.

[0045] The present invention provides an organic laser, preferably a low-threshold organic laser, wherein the organic laser comprises the above-mentioned organic single crystal dye laser.

[0046] Beneficial effects of the present invention:

[0047] The organic single crystal dye laser of the present invention has the following advantages:

[0048] 1. The organic single crystal dye laser provided by the present invention has a micro-nano structure, such as a micrometer wire structure, which can be used as a high-quality optical resonant cavity to provide optical feedback and mode selection for stimulated radiation of the dye single crystal, and can effectively output coherent optical signals in a directional manner;

[0049] 2. The organic dye single crystal provided by the present invention has a large molecular distance and weak intermolecular interaction, which inhibits the intermolecular charge transfer process, maintains sufficient optical gain properties of the dye in the aggregated state, and is conducive to establishing a population inversion to achieve the final laser radiation (such as low-threshold laser emission);

[0050] 3. The inventors have found that in the excited state process of the organic single crystal dye laser, there is a large potential barrier from the intramolecular charge transfer state to the intermolecular charge transfer state energy level, and the intermolecular charge transfer state that is unfavorable to stimulated radiation will not be generated, thereby having a faster radiation transition rate;

[0051] 4. The inventors have found that the dye single crystal is a kinetic product obtained by accelerating the self-assembly process. By controlling the experimental temperature, the molecular assembly process can be regulated, thereby avoiding the formation of thermodynamic dye single crystals that are unfavorable to stimulated radiation due to the close stacking of molecules;

[0052] 5. The inventors have found that the organic single crystal dye laser can effectively inhibit the charge transfer between molecules due to its weakened intermolecular π-π force, and thus can achieve stimulated radiation (such as low-threshold laser emission) in the gain range of the dye (for example, 505-515nm), demonstrating the great potential of dynamically controlled dye single crystals in constructing organic single crystal lasers.

[0053] 6. The inventors have realized optically pumped laser radiation in the organic dye single crystal for the first time, and adjusted the mode spacing of the laser by changing the size of the organic dye single crystal. The organic dye single crystal laser can be used to realize small-sized micro-nano coherent light sources, and to integrate photonic circuits to achieve improved laser performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a flow chart of the preparation process of the organic single crystal dye laser of Example 1.

[0055] Figure 2 This is a morphology characterization diagram of the organic single crystal dye laser in Example 1.

[0056] Figure 3 This is the X-ray diffraction result diagram of the organic single crystal dye laser in Example 1.

[0057] Figure 4 This is a diagram of the molecular arrangement structure of the organic single crystal dye laser in Example 1.

[0058] Figure 5 This is the micro-area Raman result diagram of the organic single crystal dye laser in Example 1.

[0059] Figure 6 This is the fluorescence emission spectrum of the organic single crystal dye laser in Example 1.

[0060] Figure 7 is the fluorescence quantum yield of the organic single crystal dye laser in Example 1.

[0061] Figure 8 This is the fluorescence decay curve of the organic single crystal dye laser in Example 1.

[0062] Fig. 9 This is a graph showing the fluorescence lifetime results of the organic single crystal dye laser at different fluorescence wavelengths in Example 1.

[0063] Fig.10 Schematic diagram of the energy levels of the organic single crystal dye laser in Example 1 and the corresponding excited state process.

[0064] Fig.11 This is the simulation result of the electric field distribution of the organic single crystal dye laser in Example 1.

[0065] Fig.12 The laser properties of the organic single crystal dye laser in Example 1 are characterized. DETAILED DESCRIPTION

[0066] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0067] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0068] Example 1

[0069] The preparation method of organic single crystal dye laser is as follows:

[0070] 1) dissolving an organic dye molecule C153 (purchased from TCI (Shanghai) Chemical Industry Development Co., Ltd., model: C2858) in n-hexane solvent to obtain a dye solution with a concentration of 2 mmol / L;

[0071] 2) placing the dye solution in step 1) on a hot plate at 40° C., stirring at 1500 rpm for 30 min and then allowing to stand;

[0072] 3) filtering the solution of step 2) through a polytetrafluoroethylene filter with a diameter of 0.2 μm to obtain a saturated solution of the organic dye molecule C153;

[0073] 4) dripping the 40° C. saturated solution prepared in step 3) onto a glass sheet at room temperature (20° C.), and placing the solution in an ethanol atmosphere, and after the n-hexane solvent evaporates completely, the organic dye molecules C153 self-assemble to obtain a dye single crystal with a micrometer wire structure, which is the organic single crystal dye laser of this embodiment;

[0074] The size of the dye single crystal can be achieved by controlling the volume of the saturated solution added in step 4). In step 4), the volumes of the saturated solution added on the glass sheet are 10 μL, 15 μL, 20 μL, 25 μL, 30 μL, 40 μL, and 50 μL, respectively. The sizes of the corresponding micrometer wire structures of the prepared dye single crystals are 3.6 μm*1 μm*560 nm, 5.1 μm*1.1 μm*500 nm, 7.3 μm*1.4 μm*510 nm, 9.1 μm*1.3 μm*560 nm, 10 μm*2 μm*600 nm, 12.5 μm*1.2 μm*700 nm, and 15.8 μm*2.2 μm*800 nm, respectively.

[0075] Figure 1 FIG. 1 is a flow chart of the preparation process of the organic single crystal dye laser of Example 1. Figure 1 It can be seen that in the hot solution of organic dye molecules C153 (for example, 40°C), the dye molecules are uniformly dispersed in the solvent with large intervals. After the hot solution of organic dye is drop-cast on a substrate at room temperature, the droplets of the hot solution undergo rapid molecular nucleation driven by volatilization and cooling, forming a crystal nucleus with loose molecular stacking, and further inducing molecular epitaxial growth into a dynamic dye single crystal. The dynamic dye single crystal with a large molecular interval provides the possibility of maintaining sufficient optical gain of the dye molecules.

[0076] Test Example 1

[0077] The organic single crystal dye laser of Example 1 was subjected to the following morphological structure analysis and fluorescence performance characterization:

[0078] 1. Morphology characterization test

[0079] Figure 2 This is a morphology characterization diagram of the organic single crystal dye laser in Example 1. The dimensions of the organic single crystal dye laser are: A is 12.5μm*1.2μm*700nm; B is 7.3μm*1.4μm*510nm; C and D are both 10μm*2μm*600nm. Figure 2 A, B, C, and D in the figure are morphological representations of the organic single crystal dye laser obtained in Example 1. Figure 2 A in the figure is a scanning electron microscope image, and the scale bar is 2 μm; Figure 2 B in the figure is the photoluminescence image, and the scale bar is 2 μm; Figure 2 C in the figure is a transmission electron microscope image, and the scale bar is 500 nm; Figure 2 D in the figure is the selected area electron diffraction pattern, and the scale is 2 1 / nm.

[0080] Depend on Figure 2 From A in the figure, it can be seen that the organic single crystal dye laser of Example 1 is a one-dimensional micrometer line structure, which has a smooth surface and a regular end face. The length of the micrometer line is 12.5 μm, the width of the micrometer line is 1.2 μm, and the thickness of the micrometer line is 700 nm. Figure 2 From B in the figure, we can see that the organic single crystal dye laser emits bright blue light under ultraviolet light (the bright color in the figure is the bright blue light in the color picture), and has typical optical waveguide characteristics, such as bright light emission at its end and weak light emission in the body of the micron wire, which indicates that the micron wire can better confine the propagating photons and produce optical resonance. Figure 2As shown in C and D in FIG, the transmission electron microscope image (TEM) and the corresponding selected area electron diffraction (SAED) of the organic single crystal dye laser of Example 1 show that the micrometer wire of the organic dye single crystal grows along the

[012] direction, and the (012) and (210) interplanar spacing values ​​are respectively and This is consistent with the X-ray diffraction (XRD) results of the organic single crystal dye laser.

[0081] 2. Molecular arrangement structure

[0082] (1) Figure 3 This is the X-ray diffraction result of the organic single crystal dye laser of Example 1. The size of the organic single crystal dye laser is 10 μm*2 μm*600 nm. Figure 3 It can be seen that the organic single crystal dye laser with micrometer wire structure has a high degree of crystallinity, and the XRD spectrum can be well indexed to the triclinic system, and its unit cell parameters are α=80.231°, β=78.024°, γ=74.093°. combine Figure 2 B, C and Figure 3 Through the analysis, the crystal structure of the organic single crystal dye laser was clarified, which provided conditions for further specific analysis of its molecular arrangement.

[0083] (2) Figure 4 This is a molecular arrangement structure diagram of the organic single crystal dye laser of Example 1. The size of the organic single crystal dye laser is 10 μm*2 μm*600 nm. Figure 4 A in the figure is the face-to-face molecular arrangement structure of the smallest periodic unit of an organic single crystal dye laser. Figure 4 Where B is a parallel face-to-face molecular arrangement with the smallest π-π spacing. Figure 4 As shown in Figure A, the repeating unit along the face-to-face π-π stacking direction consists of three parallel organic dye molecules C153, and there are three π-π intermolecular interactions in the crystal phase of the organic single crystal dye laser, corresponding to two antiparallel and one parallel molecular stacking modes. Since the distance of parallel molecular stacking is the smallest, it has the greatest impact on the luminescence of the organic dye molecule C153, and is determined by Figure 4 From B, we can see that the intermolecular distance of the parallel molecular stacking of the kinetic dye single crystal is This molecular spacing is relative to the molecular spacing of the tightly packed thermodynamic C153 dye single crystal The loose molecular stacking in the kinetic dye single crystal is conducive to suppressing the intermolecular charge transfer in the organic single crystal dye laser, making stimulated emission more likely.

[0084] (3) Figure 5This is the micro-area Raman result of the organic single crystal dye laser in Example 1. The size of the organic single crystal dye laser is 10μm*2μm*600nm. Figure 5 It can be seen that the organic single crystal dye laser has a wavelength of 1159 cm -1 There is a CC single bond stretching vibration peak at 1608.19 cm-1, while the stretching vibration peak of the C=C double bond is at 1608.19 cm-1. -1 Compared with the C=C stretching vibration peak (1597.78 cm -1 ) blue-shifted, further indicating that the organic single crystal dye laser has a weaker π-π stacking interaction.

[0085] 3. Fluorescence performance test:

[0086] (1) Figure 6 The fluorescence emission spectrum of the organic single crystal dye laser in Example 1, the size of the organic single crystal dye laser is 10μm*2μm*600nm. Figure 6 It can be seen that the organic single crystal dye laser emits cyan light under the excitation of ultraviolet light (330-380nm), and its maximum emission wavelength is at 516nm.

[0087] (2) Figure 7 is the fluorescence quantum yield of the organic single crystal dye laser in Example 1, and the size of the organic single crystal dye laser is 10μm*2μm*600nm. Comparing the fluorescence emission spectra without and with samples (the two overlap more at 405nm), the formula Φ PL =A em / (A ex,no sample –A ex,with sample ) can obtain the quantum yield of the organic single crystal dye laser, wherein A em is the integrated area of ​​the sample emission spectrum, A ex,with sample and A ex,no sample are the integrated areas at 405nm excitation light with and without samples, respectively. Figure 7 It can be seen that the quantum yield of the organic single crystal dye laser is 59.8%, which is much higher than the quantum yield of the organic dye single crystal with intermolecular charge transfer, which is very beneficial for light amplification.

[0088] (3) Figure 8 is the fluorescence decay curve of the organic single crystal dye laser in Example 1, and the size of the organic single crystal dye laser is 10 μm*2 μm*600 nm. Figure 8 It can be seen that the fluorescence intensity of the organic single crystal dye laser decays exponentially with time. Further fitting analysis shows that its fluorescence lifetime τ is 1.53ns, which is much smaller than the fluorescence lifetime of the dye single crystal with intermolecular charge transfer. Figure 7 and Figure 8 The result is that according to the formula, the radiation transition rate k r =Φ PL / τ, the calculated radiation transition rate of the organic single crystal dye laser is 0.39ns -1 , this faster radiation transition is conducive to the occurrence of stimulated emission.

[0089] (4) Fig. 9 The fluorescence lifetime results of the organic single crystal dye laser at different fluorescence wavelengths in Example 1 are shown in FIG. The size of the organic single crystal dye laser is 10 μm*2 μm*600 nm. Fig. 9 It can be seen that different fluorescence wavelengths of the organic single crystal dye laser correspond to different fluorescence lifetimes, and as the fluorescence wavelength increases, the fluorescence lifetime of the organic single crystal dye laser increases accordingly (for example, the fluorescence wavelengths are 480nm, 500nm, 520nm, 540nm, 560nm, and 580nm, and the corresponding fluorescence lifetimes are 1.22ns, 1.44ns, 1.63ns, 1.83ns, 2.23ns, and 2.47ns), indicating that the emission of the organic single crystal dye laser at 516nm originates from the monomer emission in the intramolecular charge transfer state (the localized monomer emission is manifested as the fluorescence lifetime remaining relatively unchanged with the increase of the fluorescence wavelength).

[0090] (5) On this basis, the inventors proposed an excited state physical model of an organic single crystal dye laser, such as Fig.10 Schematic diagram of the energy level of the organic single crystal dye laser of Example 1 and the corresponding excited state process. Fig.10 It can be seen that under light excitation, the organic dye molecule C153 vertically transitions from the ground state to the localized state, and quickly falls back to the intramolecular charge transfer state. Organic single crystal dye lasers have loose molecular stacking and weak π-π stacking interactions, which make it difficult for the monomer state of intramolecular charge transfer to transfer charge to unexcited adjacent molecules, thereby inhibiting the formation of intermolecular charge transfer states. Since the intramolecular charge transfer state has a smaller degree of charge separation than the intermolecular charge transfer state, corresponding to a larger overlap of wave functions between the ground state and the excited state, the dynamic organic dye single crystal has a greater probability of radiative transition, which is expected to provide effective optical gain for the realization of single crystal dye lasers.

[0091] It can be seen from the above characterization results that the organic single crystal dye laser obtained in Example 1 has excellent optical gain.

[0092] Test Example 2

[0093] The electric field distribution of the organic single crystal dye laser (size: 10 μm*2 μm*600 nm) of Example 1 was simulated as follows:

[0094] Test instrument: COMSOL electric field distribution simulation software.

[0095] Testing process:

[0096] (1) In the simulation software, draw a two-dimensional rectangular structure with a length of 10 μm and a width of 2 μm, representing the dye single crystal with a micron-wire structure prepared as described above, and set its refractive index to 1.56;

[0097] (2) Draw a large rectangular structure with a length of 16 μm and a width of 12 μm to represent the external environment around the micron-wire single crystal - air, and set the refractive index of this large rectangular structure to 1;

[0098] (3) Input the characteristic frequency formula corresponding to the laser wavelength of 510nm of the micron-wire single crystal: c_const / 510[nm]; the software starts to calculate the electric field distribution intensity.

[0099] like Fig.11 is the simulation result of the electric field distribution of the organic single crystal dye laser in Example 1. Fig.11 It can be seen that along the axial distribution of the organic dye single crystal micron wire (such as Fig.11 The optical mode of the image (in the direction of the arrow marked in the figure) clearly shows that Fig.11 The rectangle (10 μm long and 2 μm wide) containing an elliptical light spot in the center is reflected back and forth along the two end faces of the micron-wire structure. It can be seen that the high-quality optical resonant microcavity of the organic single crystal dye laser is a typical Fabry-Perot microcavity.

[0100] Test Example 3

[0101] The organic single crystal dye laser of Example 1 was subjected to femtosecond light excitation test under femtosecond light pumping.

[0102] Femtosecond light excitation test instrument: A spatially resolved micro-area spectroscopy test system was built, including a 800nm ​​wavelength titanium-doped sapphire laser (pulse width 100-200fs, repetition frequency 1KHz); nonlinear optical crystal β-BaB2O4 (BBO); a microscope system; and a spectrometer.

[0103] The test process of femtosecond light excitation: 800nm ​​wavelength laser is output by titanium-doped sapphire laser, and the light beam is frequency-doubled by nonlinear optical crystal β-BaB2O4 (BBO) to a femtosecond pulse laser with a wavelength of 400nm. All lasers are passed through a 720nm short-pass filter to obtain a relatively pure femtosecond laser with a wavelength of 400nm. The 400nm femtosecond laser enters the microscope system after reflection, and is focused by a 50x objective lens into a light spot of about 20μm, which is used as a light source to excite the organic single crystal dye laser of Example 1. Subsequently, the same objective lens is used to collect the signal light emitted by the organic single crystal dye laser of Example 1. The collected signal light is filtered out by a 420nm long-pass filter to remove the excitation light, and then analyzed by a spectrometer.

[0104] Test conditions: The spectrometer software needs to be run at a low temperature of -75°C, the temperature of the circulating water cooling system of the titanium sapphire laser is set to 21°C, and the organic single crystal dye laser of Example 1 can be tested at room temperature.

[0105] like Fig.12 The laser properties of the organic single crystal dye laser in Example 1 are characterized. Fig.12 The scale bar in the inset of Figure A is 5 μm, which corresponds to the size of the organic single crystal dye laser: 10 μm*2 μm*600 nm. Fig.12 As shown in A, when a single organic single crystal dye laser is excited by femtosecond light, very bright light emission behavior appears at both ends of the organic single crystal dye laser, indicating that the emitted light is significantly modulated by the high-quality Fabry-Perot resonant cavity. 2 Increased to 186μJ / cm 2 , the optical mode around 510nm in the emission spectrum of organic single crystal dye lasers is significantly amplified. Fig.12 B in Figure 1 further analyzes the relationship between the spectral intensity and the spectral half-maximum full width to the pump power and finds that the corresponding curves show obvious nonlinear behavior accompanied by a rapid narrowing of the emission spectrum half-maximum full width, further proving that the organic single crystal dye laser successfully achieves laser emission.

[0106] Depend on Fig.12 It can be seen from C that as the size of the organic single crystal dye laser increases, the laser mode spacing distance L decreases. In the figure, L = 15.8 microns represents that the size of the laser is 15.8μm*2.2μm*800nm, and the corresponding laser mode spacing distance is 1.75nm; L = 9.1 microns represents that the size of the laser is 9.1μm*1.3μm*560nm, and the corresponding laser mode spacing distance is 3nm; L = 7.3 microns represents that the size of the laser is 7.3μm*1.4μm*510nm, and the corresponding laser mode spacing distance is 3.77nm. Fig.12 In Figure D, the horizontal axis is the reciprocal of the length of the organic single crystal dye laser. The figure can be further used to analyze the relationship between the mode spacing and the length of the organic single crystal dye laser in organic single crystal dye lasers of different sizes. Among them, the organic single crystal dye lasers with sizes of 15.8μm*2.2μm*800nm, 12.5μm*1.2μm*700nm, 10μm*2μm*600nm, 9.1μm*1.3μm*560nm, 7.3μm*1.4μm*510nm, and 5.1μm*1.1μm*500nm have corresponding mode spacings of 1.5nm, 1.8nm, 2.8nm, 3nm, 3.7nm, and 5.3nm, respectively. This confirms that the laser mode in the organic single crystal dye laser is a Fabry-Perot type resonance mode.

[0107] Depend on Fig.12 It can be seen that based on the excellent optical gain of the loosely packed dye molecules and the high-quality optical resonant cavity, we have achieved laser emission in organic dye single crystals for the first time and successfully constructed a low-threshold organic single crystal dye laser. Through the temperature-controlled molecular dynamics self-assembly strategy, we have prepared an organic single crystal dye laser with weak π-π interactions to inhibit intermolecular charge transfer.

[0108] The above results show that the organic single crystal dye laser obtained in Example 1 can be used in the field of organic micro-nano lasers, and can even be used in the field of integrated photonics and organic electrically driven lasers due to its excellent optical gain and high-quality optical resonant cavity.

[0109] The present invention realizes a single crystal dye laser by adjusting molecular stacking, from which it can be seen that high-performance photonic materials are expected to be developed based on molecular arrangement engineering. The organic single crystal dye laser of the present invention has great prospects in optoelectronic applications.

[0110] The above is a description of the exemplary embodiments of the present invention. However, the protection scope of the present application is not limited to the above embodiments. Any modification, equivalent substitution, improvement, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An organic single crystal dye laser, characterized in that: The organic single crystal dye laser comprises a dye single crystal, and the dye single crystal is obtained by self-assembly of organic dye molecules; the organic dye molecules are selected from coumarin-153; The dye single crystal is a triclinic system, and its unit cell parameters are a = 9.1467 Å, b = 10.8992 Å, c = 14.9339Å, α = 80.231°, β = 78.024°, γ = 74.093°; In the dye single crystal, the organic dye molecules have a loose molecular arrangement structure, which inhibits the charge transfer between molecules and realizes stimulated radiation.

2. The laser according to claim 1, characterized in that In the molecular arrangement structure, the minimum periodic unit is formed by the parallel stacking of the organic dye molecules; the distance between the parallel stacked molecules is greater than 3.587 Å; The dye single crystal has a micro-nano structure; the micro-nano structure has optical waveguide characteristics, can confine propagating photons and generate optical resonance.

3. The laser according to claim 1, characterized in that The structure of coumarin-153 is shown in Formula 1: Formula 1; The self-assembly of the organic dye molecules includes: the organic dye molecules self-assemble under weak intermolecular forces to obtain the dye single crystal.

4. The laser according to claim 1, characterized in that The dye single crystal has optical gain; the organic single crystal dye laser emits cyan light under the excitation of ultraviolet light; The organic single crystal dye laser has a fluorescence quantum yield of 59.8% under the excitation of 405 nm.

5. The laser according to claim 1, characterized in that In the molecular arrangement structure, the minimum periodic unit is 5 organic dye molecules stacked in parallel; in the dye single crystal, the distance between parallel stacked molecules is 3.632 Å; The dye single crystal has a micron-wire structure; the length of the micron-wire structure is 3-30 µm, the width of the micron-wire structure is 0.8-2.5 µm, and the thickness of the micron-wire structure is 0.3-1 µm; The dye single crystal has an optical resonant microcavity, specifically a Fabry-Perot type microcavity.

6. The method for preparing an organic single crystal dye laser according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: 1) Dissolving organic dye molecules in an organic solvent to obtain a saturated organic solution; 2) The saturated organic solution prepared in step 1) is dripped onto the substrate, and in an anti-solvent atmosphere, the organic dye molecules are self-assembled to obtain the organic single crystal dye laser.

7. The preparation method according to claim 6, characterized in that: In step 1), the organic solvent is selected from n-hexane; In step 1), the molar concentration of the organic dye molecules in the organic solvent is 1-10 mmol / L; In step 1), the preparation method of the saturated organic solution specifically includes: dissolving the organic dye molecules in an organic solvent, stirring at different temperatures to obtain organic solutions at different temperatures; filtering to obtain a saturated organic solution; the stirring temperature is 30-80°C; the stirring speed is 800-2000 rpm; and the stirring time is 15-60min.

8. The preparation method according to claim 6, characterized in that: In step 2), the anti-solvent atmosphere is selected from ethanol; In step 2), the temperature of the substrate is 10-30°C; In step 2), the self-assembly of the organic dye molecules is self-assembly induced by the volatilization of organic solvents; the temperature of the self-assembly is 30-80°C.

9. Use of the organic single crystal dye laser according to any one of claims 1 to 5, characterized in that: The organic single crystal dye laser is used in organic micro-nano lasers, integrated optical circuits and organic lasers.

10. A micro-nano laser, characterized in that: The micro-nano laser comprises the organic single crystal dye laser according to any one of claims 1-5.

11. An integrated optical circuit, characterized in that: The integrated optical circuit comprises a coherent light source, and the coherent light source comprises the organic single crystal dye laser according to any one of claims 1-5.

12. An organic laser, characterized in that: The organic laser comprises the organic single crystal dye laser according to any one of claims 1 to 5.

13. The organic laser according to claim 12, characterized in that: The organic laser is a low-threshold organic laser.

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